Immobilization of biologically active substances in a porous support

Abstract

Biologically active substances such as enzymes are immobilized in the pores of a porous support material by introducing a solution of the biologically active substance into the pores of the support material, treating the active substance in the pores to temporarily retain the active substance in the pores and immobilizing the active substance in the pores by crosslinking. Temporary retention of the active substance in the pores may be carried out by precipitation with a precipitating agent or by freeze-drying.

I claim: 
     
       1. A method for the preparation of a porous support material having a biologically active substance immobilised in the pores thereof comprising selecting a porous support material having a pore size and pore structure that permits entry of a solution containing biologically active substance, introducing said solution into the pores of said porous support material so as to substantially fill the pore volume of said support material, freeze-drying the volume of said solution introduced into the pores so as to retain said biologically active substance in the pores of the porous support material and hold the biologically active substance available for cross-linking, cross-linking the biologically active substance in the pores of the porous support material, said introduction of solution of containing biologically active substance and said freeze-drying being conducted so as to provide a major proportion of the immobilised biologically active substance in the pores of, rather than on the external surface of, the porous material. 
     
     
       2. A method as claimed in claim 1, wherein after the retention of the substance in the pores of the porous support material by freeze-drying, but prior to cross-linking, further biologically active substance is introduced into the porous support material by immersion in a concentrated solution of the substance, and is retained by treatment with a precipitating agent.